a) Field of the Invention
The invention relates to headphones. Such headphones always comprise at least one, preferably two, earpieces, which are each equipped with a reproduction transducer. Furthermore, corresponding earpieces also comprise an ear cushion, which either encloses the user's ear when the headphones are put on or lies on the ear.
b) Description of the Related Art
FIG. 1 shows a known, typical embodiment of an earpiece of headphones. Here it can be seen that the headphones earpiece consists of a housing 9, which contains a dynamic transducer system 13 in which a diaphragm 2, 3 is deflected when electric signals are applied to the system so that a sound, which travels through the outlet apertures 1 of the housing to the human ear, is produced by the diaphragm 3.
The earpiece comprises an ear cushion ring 6, which encloses the ear 5 when it is put on, so that a part of the earpiece housing 7 and the ear cushion 6 is defined by the diaphragm 2, 3 and also a volume, the so-called front volume 4, is defined by the user's head and ear 5.
The space behind the diaphragm 2, 3 and the interior of the housing 9 of the headphones shell is always described as the rear volume 8.
The front volume 4 and the rear volume 8 are also connected to one another by an acousic resistor 11. The acoustic resistor 11—e.g. a layer of paper—is situated next to the ear cushion 6 in the represented example, slightly above the plane which is described by the sound outlet apertures.
Depending on how strongly the ear cushion is now pressed against the user's head, the ear cushion becomes wider and then covers the acoustic resistor 11 to a greater or lesser extent. As the degree to which the acoustic resistor is covered by the ear cushion depends on the respective adjustment pressure and this in turn depends on the head size and the setting of the headphones, an undefined covering of the acoustic resistor by the air cushion results in there being an undefined acoustic resistance between the front chamber 4 and the rear chamber 8, so that finally the sound impression is falsified.
Headphones with general characteristics as described above are known from Patent 101 40 663 which was not a prior publication. Moreover, known from DE 197 20 396 are headphones having an acoustic unit for converting an audio signal into an acoustic sound and a storage device for storing the acoustic unit, with the predetermined distance to a user's ear being retained.